Calculate exFAT checksum

[PokePango]

Hello,

I'm want to re-calculate the checksum of a disk's VBR but I can't get the good result, when I plug it into Windows I get a fatal error and the disk isn't recognized.

I saw this topic related to ML: https://groups.google.com/forum/#!topic/ml-devel/EWHU5ukyMt4

But it doesn't works... I also tried to copy/paste the related sectors directly into the script (with an hexa editor) but still the result isn't correct. Am I missing something? I copy the data from sector 0 of the VBR (offset 2048 on my disk) up to sector 10 which corresponds to 5632 bytes, calculate the checksum and don't have the right result!

Can anyone help me? Thanks!

[Overcertified]

If you are doing what you say, then you are doing it wrong.

In the first VBR record there are I think 3 bytes that are excluded ftom the calculation.

There is information on in Robert Shullich sand paper and a program on his blog at rshullic.Wordpress.com where you can extract the algorithm as well.